SYDNEY, Oct 5 (Reuters) - Iron ore shipments to China from Australia's Port Hedland, a bellwether for Chinese industrial activity, fell by 9.5 percent in September from the previous month to be flat on the year, port authority data showed.

September shipments to China dipped to 15.13 million tonnes, from 16.72 million tonnes in August, according to the data. That was unchanged from September last year.

Iron ore prices steadied just above $100 a tonne in September after falling sharply through July and August to reach as low as $86.70 at one stage.

The steel ingredient has been the hardest hit among industrial commodities by China's slowdown, with its price dropping by more than a third this year.

Australia is China's single largest source for imported iron ore, followed by Brazil.

Total iron ore shipments from Port Hedland in September were 19.9 million tonnes, down from 22.8 million in August and 20 million in September last year.

BHP Billiton is the port's biggest user, followed by Fortescue Metals Group Ltd .

Japan imported 2.1 million tonnes in September, versus 2.4 million tonnes in August. September shipments to South Korea were 1.9 million tonnes against 2.7 million tonnes in August.